1. Technical Field
The present invention relates to a resonator element, a resonator, an oscillator, an electronic apparatus, and a moving object.
2. Related Art
An AT cut quartz crystal resonator element has thickness shear vibration as a vibration mode of main vibration for excitation, and is suitable for miniaturization and realizing high frequency. In addition, the AT cut quartz crystal resonator element shows a third-order curve which is superior in a frequency-temperature characteristic, and is thus used in various applications such as piezoelectric oscillators and electronic apparatuses.
As such an AT cut quartz crystal resonator element, JP-A-2009-164824 discloses an embodiment of an AT cut quartz crystal resonator element with an inverted mesa structure which is a structure in which, for example, thick portions are respectively connected to three sides of a rectangular thin vibration portion, and one side of the thin vibration portion is opened from the thick portions. With this configuration, a wide vibration region can be secured, and miniaturization can be achieved.
However, in the AT cut quartz crystal resonator element of the embodiment, since the open width is the same as a width of the vibration portion in the same direction as the open width, if vibration (particularly, acceleration in the thickness direction) is applied thereto, the vibration portion is deformed. If the vibration portion is deformed, a vibration characteristic varies, and thus there is a problem in that a desired oscillation characteristic cannot be obtained.